Temps not reaching 90

[arman123]

Hi my car is booked into audi this Friday because the temp is not hitting 90 had the cambelt waterpump and thermostate changed by audi in July even on a motorway run yesterday about 40 miles did not reach 90 always under about 80/85 ish Mpg has suffered aswell had a full scan done no codes so think the coolant temp sensor is ok 2 weeks before I had the work done by audi I changed the coolant temp sensor my self a genuine green one so looking for some good info to go to audi with so they dont rip me off I'm sure it's a sticking thermostate So any help people

[Issac Hunt]

Why are they going to "rip you off"? They will charge you for their time and parts they use, but they are a business not a charity.

If you are sure what the fault is, why are you taking it to Audi to be "ripped off"? Why not just repair it yourself and save some money? Or find an independant garage?

It could well be a stuck/faulty thermostat, could be plenty of other things as well , (coolant temp sensor, faulty dashboard/wiring etc etc) - there is no crystal ball sadly. Using VAGCOM to check and read the fault codes and measuring blocks might help you track the fault down.

[arman123]

Why are they going to "rip you off"? They will charge you for their time and parts they use, but they are a business not a charity.

If you are sure what the fault is, why are you taking it to Audi to be "ripped off"? Why not just repair it yourself and save some money? Or find an independant garage?

It could well be a stuck/faulty thermostat, could be plenty of other things as well , (coolant temp sensor, faulty dashboard/wiring etc etc) - there is no crystal ball sadly. Using VAGCOM to check and read the fault codes and measuring blocks might help you track the fault down.

Because they fitted the thermostat in the first place I thought il have it done as they were doing the cambelt and water pump temp were fine before they changed the thermostate also no faults with Vcds how can I use vcds to track down the fault

[mikeybutch]

If the temp hasnt been right since the stat was fitted seems likely to be faulty.Is the heater slow to have effect thats usually a sign of a stat stuck open

[NickPicks]

If Audi changed the thermostat 2 weeks ago and it's not working properly, then it comes with a 2 year parts and labour warranty, so if the thermostat is faulty, they'll be fixing it free of charge.

[Fogster9]

I had a new thermostat fitted 4 week ago not by Audi by a Vag garage, same thing temperature gauge started to read below 90c. Took it back to garage they fitted a new one and all as been good since.

New thermostat's can fail.

[arman123]

thank guys for the replys when i was on the phone with audi today they said if its a repair they have done and found to be faulty then they will fix free of charge if not it will be £140. i was thinking how will they be able to diagnose a faulty thermostat or will they just replace it i have scanned my car with vcds and no faults at all so the last thing i want them to say is faulty coolant temp sensor because i know its not it should throw up a code if it was plus the temp gauge would be erratic any ways will see on Friday thanks people

[mikeybutch]

If you make it clear that the temp is not right and they agree and accept this then the stat is changed and all is as it s/b then they must accept that the stat was faulty.I think that it is difficult to test a stat unless its totally failed

[Fogster9]

Well when my new TS went faulty I did have to argue the toss, he put it on the Vag com and said everything was reading right ( something about blocks or something) anyway he'd said that he didn't think it was the TS, I said it must be because it was ok for a few days when they fitted it the 1st time. I'd changed the sender the week before. I ended up telling them I would get it changed somewhere else and they could remiburse if it was the TS.

They then agreed to change it there and then and as been fine since. I was worried about having egg on my face if it wasn't the thermostat tho.

[arman123]

ok update car went in to the dealers today few hours later get a phone call saying the technician has looked at the car and the TS is faulty and will be replaced.
ok fine just as i thought hour later another call saying the technician thinks the car is not sending enough heat into the cabin he thinks it could be the water pump so he wants to change that i said ok fine its under the 2 year parts warranty so why not then hour later again another call now the technician is saying the radiator is blocked and it will be £420 to fit a new one so i said no thanks i will pick the car up bit weird wont a blocked radiator cause the car to overheat.Heat in the car is fine from the heaters when i drove it back.the car went in in the first place for over cooling what do you guys think? and one more thing looks like they overfilled the coolant will that just drain off from the overfill

[mikeybutch]

So did the replace the stat and pumpFOC?I hope so.I agree rad is unlikely to be blocked if the car wasnt overheating and is now fine .You can check by getting it up to temp switching off and feeling the rad topto bottom it s/b about the same temp but if the bottom is cold there is some sludge there which you may be able to flush out .If the rad feels OK and they are trying it on then syphon off the excess coolant ASAP.Its a sealed pressurised system and something could pop if theres too much in there

[arman123]

ok will do the coolant thanks.yes they did replace the stat and pump free of charge funny was when i told the lady there wont a blocked rad make the car overheat she did not know what to say she goes thats what tech said asked if i could speak to him she said he gone home mind you it was 6:00pm today when i picked the car up thats the time they close anyways cars up to temp so all good hope they aint messed any thing else up

[macp]

I sympathise having experienced the same temp issues. I changed the temp sender and the stat and I flushing and changing the coolant on monday in the hope it will resolve it once and for all.

[mikeybutch]

I think mixing antifreezes is a cause of rad blockages

[arman123]

Never mixed the antifreeze on my car bought it in 2008 off a lady owner and she serviced all at dealers just thinking rad blocked would that overheat?

[mikeybutch]

It must overheat at any reasonable speed after not many miles cos the engine needs all the rad to cool and if theres a lot of sludge at the bottom it willreduce its efficiency although the coolant will still circulate.It would happen quicker on a hot day than if it was freezing.Its unusual if the right antifreeze has always been used and I would never trust garage servicing 100%

[arman123]

It must overheat at any reasonable speed after not many miles cos the engine needs all the rad to cool and if theres a lot of sludge at the bottom it willreduce its efficiency although the coolant will still circulate.It would happen quicker on a hot day than if it was freezing.Its unusual if the right antifreeze has always been used and I would never trust garage servicing 100%

never had the car overheat on me since i bought it even 100 miles plus trips on the motorway never overheated once was suprised when the dealers said rad was blocked. he said something about not enough heat the heaters are producing so he changed the water pump i said i never had a problem with the heats in the car but the water pump was under warranty so i said fine then they said rad blocked and wanted to charge me £450 to change it i just said park the car outside and il come to collect it just thinking have i made the right decision? as the car not overheating i think the rad should be fine.

[mikeybutch]

That settles it the rad is OK but you could check by feeling and I would ask why they said it was blocked .

[nevo]

If your rad was blocked it would be boiling up or at least getting high temp alarms,I think the first thing to do is change the stat again,it an easy job to do then take it from there,they can stick even new ones as previously said.

[Crasher]

I had an over cooling Passat 130 TDI in yesterday (probably the same engine) and the thermostat wasn't stuck open but when I tested it I found it opened way too early. A new genuine thermostat sorted it out.